If a six-month-old baby has a heavy urine smell, pay attention to the following two possibilities: 1, genetic metabolic disease, the most common is phenylketonuria, because of abnormal amino acid metabolism leads to excessive discharge of phenylacetic acid from urine and sweat, urine will be a special rat urine odor, most patients will be accompanied by skin hair color lightening and intellectual impairment, such as at the age of six months still can not recognize relatives, etc., need to go to the hospital for timely 2, if the baby eats too little milk or formula intake is too little, resulting in insufficient water, urine concentration, thus appearing darker urine, urine smell heavy situation, after replenishing enough water urine smell back to normal.